In order to provide information confidentiality, mutual authenticity, privacy, and anonymity, records should be kept in a distributed manner. Thus, blockchain has emerged as a feasible solution to achieve such goals. A blockchain is a decentralized and distributed ledger in which a digital record of transactions is maintained across blocks without requiring a central authority. All the blocks in the blockchain are linked in a chronological order to form a chain and secured using cryptography. Since, central managers are not involved in the blockchain structure, it is more robust against single point failure issues. Due to its wide range of benefits, blockchain-based applications, ranging from financial services to Internet of Things (IoT), are constantly expanding. Motivated by these facts, several approaches were developed in the literature in order to provide authentication in vehicular networks. For example, Lei et al. [1]} put forward a novel network topology based on a decentralized blockchain structure; wherein a blockchain was employed to simplify the distributed key management in vehicular communication systems. Kang et al. [2]} adopted the concept of consortium blockchain to achieve secure data storage and sharing in vehicular edge networks. To support conditional privacy, one-to-many matching, destination matching, and data auditability in VFC, Li et al. [3]} proposed an efficient and privacy preserving car-pooling scheme using blockchain. Accordingly, Yao et al. [4]} presented a lightweight anonymous authentication mechanism for distributed vehicular fog services using blockchain. Their primary focus was on cross-data center authentication using blockchain and cryptographic functions. However, the designed scheme did not support mutual authentication between vehicles and service managers (SMs), which is a prerequisite for any secure authentication protocol.
